Switch device with improved detent structure



Sept. 6, 1966 J. M. VANANZI SWITCH DEVICE WITH IMPROVED DETENT STRUCTUREFiled June 16, 1965 Joseph M. l/ananzi INVENTOR.

BY WWW 3M5 United States Patent 3,271,535 SWITCH DEVICE WITH IMPROVEDDETENT STRUCTURE Joseph M. Vananzi, Meadowbrook, Pa., assignor toContinental-Wirt Electronics Corporation, a corporation of PennsylvaniaFiled June 16, 1965, Ser. No. 464,380 4 Claims. (Cl. 20016) Thisinvention relates to electric switches and more particularly to detentcontrolled bridging switches having a slidable member for selectivelybridging contacts.

Previously known switches of the slidable detent bridging type haveutilized the bridging contacting members to provide means for releasablyholding the contacting members in a plurality of positions. This hasbeen accomplished in a variety of ways, including the use of resilientcontacting members with downwardly projecting detent portions whichslide between upwardly projecting electrical contacts and are therebyretained therebetween. However, the use of the contacting membersthemselevs to provide detents for indexing or positioning the contactingmembers has been generally unsatisfactory as the contacting membersgradually lose their resiliency and the contact surfaces becomeexcessively worn. Where detent structures independent of the contactmembers have been utilized, the resulting arrangement is often bulky andexpensive.

Accordingly, it is an object of the present invention to provide aswitch assembly which has contacting members for circuit connectionpurposes and separate detent means for positioning such actuator withinthe switch housing and maintaining a proper contact pressure between thecontacting members.

It is a further object of the present invention to provide a slidingcontact electrical switch of simple and economical construction, whichis easy to assemble and install and which is relatively maintenancefree.

An additional object of the invention is to provide detent facilitiesfor a sliding switch which is structurally independent of the contactelements and does not require enlargement of the size or bulk of theswitch assembly.

Another object of the present invention is to provide a detentcontrolled bridging switch in which a top mounted detent plate coactswith spaced recesses in the switch housing to position the switch withinthe housing.

These together with other objects and advantages which will becomesubsequently apparent reside in the details of construction andoperation as more fully hereinafter described and claimed, referencebeing had to the accompanying drawings forming a part hereof, whereinlike numerals refer to like parts throughout, and in which:

FIGURE 1 is a perspective view of the detent switch device comprisingthe present invention;

FIGURE 2 is an enlarged vertical sectional view taken substantiallyalong the plane of the line 2-2 of FIG- URE 1;

FIGURE 3 is a vertical sectional view taken substantially along theplane of the line 3-3 of FIGURE 2; and

FIGURE 4 is a perspective view of the various elements of the detentswitc-h device exploded apart to better show the relationshiptherebetween.

Referring now specifically to the drawings, reference numeral generallyrefers to one form of detent switch device constructed in accordancewith the present invention as best seen in FIGURE 1. The detent switchdevice includes a housing member 12 having side walls 14 and 16 and anexposed top wall 18. The top wall 18 includes an elongated guide slot 20therein as well as mounting holes 22 and 24 for mounting the switchdeice 10in a suitable manner.

3,2 7 l ,535 Patented Sept. 6, 1966 The walls 14 and 16 includedepending tabs 26 which are formed integrally therewith and which areused to retain a bottom wall or base member 28 therein. The bottom wallor base member 28 is preferably of any suitable non-conducting material,and includes recesses or slots 30 positioned along opposite longitudinaledges thereof for receiving the tabs 26. The tabs are bent into theslots and folded under the member 28 to retain the member 28 as a basefor the housing.

The housing mounts therewithin a detent plate 32, a switch actuator 34,contact elements 36 and 38 and substantially V-shaped retaining members40 and 42. The switch actuator 34 has a base portion 44 and a knobportion 46 both of which are made from insulating material. The knobportion 46 extends through the slot 20 and is slidable therealong. Thebase portion 44 of switch actuator 34 includes upstanding end bearingportion 35 and substantially parallel channels 48 and 50 in the bottomthereof. The contact elements 36 and 38 include upstanding end portions52 which come to a point and fit through the mounting holes 54 inretaining members 40 and 42. Thus, it may be observed that when theretaining members 40 and 42 are positioned on contact elements 36 and38, each retaining member and contact element forms a unit which isretained within the channels 48 and 50 when the switch device isassembled. The channels 48 and 50 include end walls 56 against which theupstanding end portions 52 are positioned when the switch device isassembled, and the upper surface of the channels have recesses 58 intowhich the apices of the retaining members are seated when the switchdevice is assembled. The retaining members 40 and 42 as well as thecontact elements 36 and 38 are formed from an electrical conductingmaterial such as brass or other non-ferrous alloys and thus conduct theflow of electricity therethrough as well as being resilient in order toexert contact pressure downwardly against the base member 28 for apurpose to be described hereinafter. The contact elements are heldassembled on the actuator 34 between the base member and the top wall 18of the housing by the detent plate 32 which includes an opening 60substantially in the middle thereof through which the knob portion 46 ofswitch actuator 34 extends. Thus, it may be observed that the detentplate 32 lies between the lower surface of the upper Wall 18 of housing12 and the upper surface of the base portion 44 of switch actuator 34when the switch device is assembled.

The detent plate 32 is preferably constructed of resilient springnon-ferrous material and is held in a stressed condition between the endbearing portions 35 of the base 44 and upper wall 18. The plate 32 isbent as at 62 and 64 to provide legs 66 and 68 and a central engagingportion 70.. The opening 60 is included in the central portion 70thereby leaving only narrow side strips 72 and 74 bridging the legs 66and 68. Also, longitudinal extensions 76 and 78 project into the opening60 and into abutment with the handle portion 46 of switch actuator 34.These extensions 76 and 78 fit tightly against the knob portion 46 andthus eliminate any play between the knob portion 46 and the detent plate32 when the switch actuator is .moved within the slot 20. Formed in thebridging portions 72 and 74 are raised detent projections or formations80 and 82 which are useful for a purpose to be described hereinafter.The detent plate 32 in its unstressed condition is slightly V-shaped;that is, the engaging portion 70 rises upwardly to an apex .at thedetents 80 and 82. Thus, it will be apparent that the detent plate whenpositioned between the base 44 and top wall 18 will be stressed intocontact wit-h the top wall to thereby exert pressure on the contactelements through the actuator and the retaining members 40 and 42.

The recesses 84 are formed in the top wall spaced longitudinally alongthe guide slot 20 into which they open. Thus, it is apparent that thedetents 88 and 82 will be engageable in the recesses 84 as the switchactuator 34 and the detent plate 3 2 are moved along the slot 20. Theengaging portion 78 will therefore flex downwardly between the endbearing portions 35 on the actuator 34 to accommodate displacement ofthe detent projections. In the embodiment described herein, there arethree recesses 84 on each side of the slot 20, but it will be apparentthat any number of recesses may be used depending upon the number ofpositions associated with the switch device. In this embodiment theswitch device has four positions with the recesses 84 offset along eachside of slot 20, thus providing four separate and distinct positions atwhich the detents 88 and 8-2 may be engaged in at least one recess 84.The detent plate 3 2 also includes the raised ribs 86 in leg portions 66and 68 in order to increase the stiffness of these portions.

The insulating base member 28 includes a plurality of electricalcontacts spaced therealong, corresponding to the desired number ofpositions and poles for the switch device. In the embodiment disclosedin this application, there are five contacts 88 spaced in two rowslongitudinally along the base member 28 thus providing a Z-pole, 4-position bridging switch. The electrical contacts 88 include terminalextensions 90 which are adapted to be connected to the wires of anelectric circuit and a lug portion 92 which extends through theinsulating base member 28 and is wrapped thereabout to lock the terminalin place, as shown in FIGURE 3. Each contact 88 includes a portion 93exposed above the base member 28 shaped to establish line contactbetween the contact elements 36 and 38 and the electrical contacts 88.

The operation of this switch device is as follows. The contact members36 and 38 electrically bridge adjacent electrical contacts 88 thuscompleting an electric circuit in the respective operative positions ofthe switch actuator 34. The detent plate 32 cooperates'with the housingto define the operative positions at which various circuits arecompleted by the contact elements 36 and 38. The flat configuration ofthe contact elements 36 and 38 as well as the configuration of the lugs92 and the downward pressure exerted through the retaining members 40and 42 ensure proper contact with the terminals orelectrical contacts88. Due to the length of the contact elements 36 and 38 no more than twoadjacent terminals 88 can be bridged in any one position of the switchactuator, and the ends of the slot 20 limit the longitudinal movement ofthe switch actuator Within the slot. Thus, it will be apparent that whenthe switch actuator is moved along the slot 28, the detent plate 3.2,the switch actuator 34, the remaining members 40 and 42 and the contactelements 36 and 38 are moved between housing 12 and base member 28 andmay be yieldably held in four separate positions by the detents 80 and82 being received in recesses 84. The resiliency of detent plate 32 andthe assembly of retaining members and contacting members insure firmanduniform electrical contact with both terminals being bridged byavoiding any variation in the fiexure of the retaining members and thecontact elements in order to establish the position holding force.Further, because of the formation of the detent notches 84 in the topwall of the housing itself and the use of a relatively thin detent plate32 disposed in close spaced relation below the top wall, substantiallyno enlargement of the switch assembly is involved in order to house thedetent facilities.

The foregoing is considered as illustrative only of the principles ofthe invention. Further, since numerous modifications and changes willreadily occur to those skilled in the art, it is not desired to limitthe invention to the exact construction and operation shown anddescribed, and accordingly all suitable modifications and equivalentsmay be resorted to, falling within the scope of the invention a claimed.

What is claimed as new is as follows:

1. In an electrical switch assembly having a rectilinearly slidableswitch actuator, electrical contact members held captive by and movablewith said actuator, an insulating support underlying said contactmembers and having paired contact terminals respectively adapted to bebridged by said contact member upon shifting movement of said switchactuation relatively to said support and an enclosing casing for saidswitch assembly having a substantially flat top wall part overlying thetop of said switch actuator and opposed depending side wall partssecured to said insulating support to embrace therebetween said SlWitChactuator, said cont-act members and said insulated contact terminals,said casing having an elongated slot in its said top wall part extendinglengthwise of said casing in parallel relation to said opposite sidewall parts thereof, and said switch actuator having an upwardlyprojecting part integral therewith extending through said slot forshifting movement within the limits of said slot, the improvementcomprising a detent plate formed of resilient sheet material disposed inintervening relation between the top wall part of the casing and the topof said switch actuator, said detent plate being centrally apertured tonon-rotatably captivate the upwardly projecting part of said switchactuator for shifting movement of the plate with said actuator, saiddetent plate being provided with laterally spaced relatively narrowparallel coplanar side strips respectively disposed at opposite sides ofthe central aperture of the plate and extending lengthwise alongopposite sides or the upwardly projecting part of the actuator inrespective parallel relation to the casing side wall parts, each of saidnarrow strips of the detent plate substantially mid-point of its lengthhaving an integrally formed detent of generally inverted U-shape asviewed from a side edge of said strip, each said detent extendingtransversely across the tfull width of its associated strip to providein the latter a pair of substantial-1y parallel flex lines spacedlongitudinally along and extending transversely of the strip to permitflexing of the strip and corresponding movement of the detentorthogonally with respect to the plane of said detent plate.

2. A detent plate for an electrical switch assembly as defined in claim1 in which said plate is provided with opposite end extensionsrespectively disposed in a substant1al common plane spaced below theplane of the apertu-red portion of said plate.

3. A detent plate for an electrical switch assembly as defined in claim1 in which said plate is provided with opposite end extensionsrespectively disposed in a substantial common plane spaced below theplane of the apertured portion of said plate, said extensions being eachprovided .with a reinforcing and rigidifying rib extending lengthwisethereof.

4. In an electrical switch assembly as defined in claim 3 wherein saidtop wall of the enclosing casing for the switch assembly is notchedalong opposite sides of the elongated slot therein at spaced pointsalong the length of said slot to provide recesses in which said detentsmay be seated to hold said actuator in a selected position, said detentsbeing arcuately shaped lengthwise of their respective strips to provideconvex surfaces favoring camming of said detents into and out of saidplate recesses.

References Cited by the Examiner I UNITED STATES PATENTS 3,121,1432/1964 Landry et al 20011 3,173,306 3/1965 Hoag 200-1 66 3,174,002 3/1965 Golbeck 200166 ROBERT K. SCHAEFER, Primary Examiner.

J. R. SCOTT, Assistant Examiner.

1. IN AN ELECTRICAL SWITCH ASSEMBLY HAVING A RECTILINEARLY SLIDABLESWITCH ACTUATOR, ELECTRICAL CONTACT MEMBERS HELD CAPTIVE BY AND MOVABLEWITH SAID ACTUATOR, AN INSULATING SUPPORT UNDERLYING SAID CONTACTMEMBERS AND HAVING PAIRED CONTACT TERMINALS RESPECTIVELY ADAPTED TO BEBRIDGED BY SAID CONTACT MEMBER UPON SHIFTING MOVEMENT OF SAID SWITCHACTUATION RELATIVELY TO SAID SUPPORT AND AN ENCLOSING CASING FOR SAIDSWITCH ASSEMBLY HAVING A SUBSTANTIALLY FLAP TOP WALL PART OVERLYING THETOP OF SAID SWITCH ACTUATOR AND OPPOSED DEPENDING SIDE WALL PARTSSECURED TO SAID INSULATING SUPPORT TO EMBRACE THEREBTWEEN SAID SWITCHACTUATOR, SAID CONTACT MEMBERS AND SAID INSULATED CONTACT TERMINALS,SAID CASING HAVING AN ELONGATED SLOT IN ITS SAID TOP WALL PART EXTENDINGLENGTHWISE OF SAID CASING IN PARALLEL RELATION TO SAID OPPOSITE SIDEWALL PARTS THEREOF, AND SAID SWITCH ACTUATOR HAVING AN UPWARDLYPROJECTING PART INTEGRAL THEREWITH EXTENDING THROUGH SAID SLOT FORSHIFTING MOVEMENT WITHIN THE LIMITS OF SAID SLOT, THE IMPROVEMENTCOMPRISING A DETENT PLATE FORMED OF RESILIENT SHEET MATERIAL DISPOSED ININTERVENTING RELATION BETWEEN THE TOP WALL PART OF THE CASING AND THETOP OF SAID SWITCH ACTUATOR, SAID DETENT PLATE BEING CENTRALLY APERTUREDTO NON-ROTATABLY CAPTIVATE THE UPWARDLY PROJECTING PART OF SAID SWITCHACTUATOR FOR SHIFTING MOVEMENT OF THE PLATE WITH SAID ACTUATOR, SAIDDETENT PLATE BEING PROVIDED WITH LATERALLY SPACED RELATIVELY NARROWPARALLEL COPLANAR SIDE STRIPS RESPECTIVELY DISPOSED AT OPPOSITE SIDES OFTHE CENTRAL APERTURE OF THE PLATE AND EXTENDING LENGTHWISE ALONGOPPOSITE SIDES OF THE UPWARDLY PROJECTING PART OF THE ACTUATOR INRESPECTIVE PARALLEL RELATION TO THE CASING SIDE WALL PARTS, EACH OF SAIDNARROW STRIPS OF THE DETENT PLATE SUBSTANTIALLY MID-POINT OF ITS LENGTHHAVING AN INTEGRALLY FORMED DETENT OF GENERALLY INVERTED U-SHAPE ASVIEWED FROM A SIDE EDGE OF SAID STRIP, EACH SAID DETENT EXTENDINGTRANSVERSELY ACROSS THE FULL WIDTH OF ITS ASSOCIATED STRIP TO PROVIDE INTHE LATTER A PAIR OF SUBSTANTIALLY PARALLEL FLEX LINES SPACEDLONGITUDINALLY ALONG THE EXTENDING TRANSVERSELY OF THE STRIP TO PERMITFLEXING OF THE STRIP AND CORRESPONDING MOVEMENT OF THE DETENTORTHOGONALLY WITH RESPECT TO THE PLANE OF SAID DETENT PLATE.